This invention relates to improved foam-producing materials which are useful for generating foam for atmospheric control in fire fighting. Fire fighting requires a "wet" foam material which retains a satisfactory water content for a considerable length of time and which forms individual bubbles which have maximum uniformity and retain their unburst form for as long as possible from a practical standpoint.
This invention relates particularly to the control of fires of two classifications: those of ordinary combustible solids, or Class A materials, which include materials such as wood, cotton, paper, etc.; and mixtures of Class A materials with Class B materials, which are flammable hydrocarbon liquids, such as gasoline, naphtha, hexane, benzene, toluene and the like.
It has been found that such foam, in order to have optimum effectiveness in putting out fires, must have a water content high enough to effect what is generally designated as a "smothering action" on the fire. This so-called "smothering action" does not mean that the foam material necessarily completely "wets" the fire, but only that enough water is entrained in the foam so that the foam will vaporize, at least in part, to form a blanket of steam, which blanket is confined by the foam in the vicinity of the fire and deprives the fire of the necessary amount of oxygen to sustain combustion.